In the medical field, a constant preoccupation is to completely prevent any form of contamination of syringe needles, before use. Usually, when a nurse even barely accidentally touches the syringe needle before use, the whole needle must be discarded, hence a cost inefficiency. The number of such accidental contamination occurrences should not be underestimated. Why is that so? This has to do with the way the needle is mounted to the syringe cylindrical body.
Indeed, conventional syringes of the disposable type come in two parts, namely a main transparent cylindrical body, having a small conical spout at one end and a large mouth bounded by a pair of fixed wings at the other end. Such a syringe is used with a needle having a bevelled tip at one end and a socket connector at the other end and inserted in a protective rigid cylindrical sheath whereby the socket connector partially engages therein. The syringe and the needle and sheath combination are both previously sterilized and enclosed in separate sealed pouches. When the nurse has to connect the needle to the cylindrical body of the syringe, she needs to follow the following steps:
(a) open the pouches
(b) take the sheath with one hand and axially engage the projecting socket connector of the needle onto the small conical end spout of the syringe cylindrical body;
(c) remove the protective sheath from its needle;
(d) note the orientation of the bevel of the needle tip with respect to the orientation of the fixed wings;
(e) replace the protective sheath on the needle;
(f) rotate the sheath and needle combination to a fraction of a turn, empirically in order to bring the needle bevel approximately parallel to the longitudinal axis of the wings;
(g) again remove the protective sheath to verify the closeness of match between the orientation of the needle bevel with the orientation of the fixed wings;
(h) repeat steps (e) to (g) until satisfactory match of the relative orientation of the needle bevel with that of the fixed wings is established.
Such match between the orientation of the needle bevel and that of the fixed wings is a standard procedure that provides a major improvement in the skin- and blood vessel membrane-piercing capability of the needle, as is very well known in the field.
It is easy to understand that such a method is inefficient: loss of time, stress sustained by the nurse, but most importantly the possibility that the nurse will touch with one finger the needle during the replacing of the protective sheath thereon, whereas the needle must then be spent and replaced by a new one. Hence, a relatively high financial outlay based on informal statistics gathered by the present inventor. Also a lot of unnecessary movements by the nurse.